I've recently finished swapping in a '00 f23 sohc vtec motor into a friends '94 civic dx.
We are running it off of an obd1 '95 Accord ex ecu.

The problem I'm running into is the car idles like crap.
It constantly fluctuates between 800 and 2000rpm rapidly, and below 2500 rpm it keeps acting like it wants to stall. But above 2500rpm it seems to run fine.

It acts as if the the tps is bad or it has a vacume leak of some sort, but it has no tps code, I've double checked the wiring to the tps and the sensor itself and everything checks out good.

I cannot locate a vacume leak of anykind.
I threw in an obd1 h22a ecu and the problem remained, idling rough and felt like it wanted to stall below 2500rpm. I then tried an obd1 LS ecu. It started hard, but once I got it started it idled smoothly and seemed to rev smoothly throughout the entire rpm range.
It seems like if it were a vacume leak, it would be affected regardless of what ecu was plugged in.

I also checked the map sensor, air intake sensor, coolant temp sensor, and all the wiring them.

The only sensor that is not figured out yet is the idle air control valve, because the '00 f23 uses a 3 wire sensor instead of the 2 wire, but I'm not sure that would cause my problem.
And if it was the cause, it would have affected it no matter what ecu was plugged in.

I've done a search for h22a idle problems(since the wiring was similar), but none of their problems were the same as mine.

Any suggestions are welcome(no matter how crazy).

I'm running out of ideas.

 

for the IAC you can use the 94-95 accord EX intake manifold this will have the two wire IAC and will give that smooth honda idle. btw you mentioned that you have no IAC connected and you're not getting any CEL. thats weird.

 

why would you put an f23 into a civic?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2trix &raquo;</TD></TR><TR><TD CLASS="quote">why would you put an f23 into a civic?</TD></TR></TABLE>
Same thing I said *shrugs shoulders and moves to next post*

 

I have to say, thats pretty cool to go with the f-series. Its good to be different.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2trix &raquo;</TD></TR><TR><TD CLASS="quote">why would you put an f23 into a civic?</TD></TR></TABLE>

Why not?

2.3 Liter
150 hp
152 tq
and he has less than $1k into the swap including HCP mounts and aftermarket header.

Faster than a b16 swap at 1/2 the price.

 

faster than a b16? how heavy is an f23?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paybac4223 &raquo;</TD></TR><TR><TD CLASS="quote"> how heavy is an f23?</TD></TR></TABLE>

Heavier than a b16, but lighter than an h22.

Who cares. Theres a difference of 41 foot lbs of torque.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paybac4223 &raquo;</TD></TR><TR><TD CLASS="quote">faster than a b16? how heavy is an f23?</TD></TR></TABLE>

it's definately faster than a b16
potential is another story tho unless he turbo's it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paybac4223 &raquo;</TD></TR><TR><TD CLASS="quote">faster than a b16? how heavy is an f23?</TD></TR></TABLE>


Why does everyone think a B16 is the best engine out there?!?! Its good, but it has it's place. The F Series (or H) weigh like 60 pounds more. The TQ they produce will more than make up there weight over the anemic B16. They will be much more "drivable" and less ***** out than the B16.

Same goes with ZC, just because it's JDM, does not mean its uber awsome. I plan on ripping the ZC out of my Civic. It came with it.

As the original poster mentioned, I would like to do a F in my Integra simply because they are really cheap compared to the other &lt;overpriced&gt; Honda motors. All I want it some more pep, and they deliver.


BTW: ya the IAC might be the problem

 

Did you ever get youur problem figured out? TPS, vacume, other?

 

cant you put a h22 or h23 head on the f22 and f23?

 

yey, they call it a g23. there are 2 guys on here that know a hell of a lot about it....
Sam1am26...and....PirateMcFred...do a search on those guys....Very interesting stuff!